In industrial control systems for controlling manufacturing processes, various parameters of the processes are sensed and action is taken based on the magnitude of the parameter. For example, when the pressure in a vessel reaches a given level, a valve may have to be opened to release the pressure. Such pressure sensors are available for use over different ranges of pressures.
The currently available sensors have enclosures which are adapted to receive one of several different types of standard plumbing fittings, such as pipe threads or compression fittings, as well as different sizes of each type. Similarly, the sensor enclosures are adapted to receive one of several different types of electrical fittings so that electrical connections may be made to the device. These electrical fittings include compression bushings for cables, conduit adaptors and different electrical connectors.
These sensor variables: pressure range, plumbing fitting and electrical fittings have heretofore required manufacturers to make and stock a wide variety of sensors having different combinations of these variables. Similarly, the end user had to stock a variety of sensors to replace ones that failed.
When the plumbing and electrical connections are made to conventional sensors, wrenches are often used to insure a tight fit. However, the use of wrenches can result in the connection being over torqued causing damage to the sensor. It is therefore desireable to provide as many connections as possible which can be made by hand and to provide a safeguard against sensor damage due to over torquing.